Please record all sources for the ratio information. This may be in the form of, but not limited to scientific literature, government reports, websites, or expert consultation. Please separate each source using a semicolon. To enter each source on a different line, click CTRL+Enter at the end of one reference to move the cursor to the next line. If citing scientific literature or reports, the preferred format is Harvardstyle, but any standard format will suffice. If available, please record the DOI as well.